# Shotgun
A shotgun is a shoulder-fired firearm with a smooth bore, designed to fire cartridges containing numerous small pellets (shot) or a single projectile (a slug) with each pull of the trigger; in some models the bore is rifled specifically for slug use.[1](https://saami.org/glossary/shotgun/) The multiple-pellet charge gives a spreading pattern that raises the chance of hitting a fast-moving target at short range, which is why the type dominates bird hunting, clay target sports, and close-range defensive and military roles.[2](https://www.firearmssafetyauthority.govt.nz/sites/default/files/2022-11/Firearms%20Safety%20Code%202022.pdf)
| Key fact | Detail |
|---|---|
| Definition | Smooth-bore shoulder firearm firing shotshells loaded with many pellets or a single slug; some bores are rifled for slugs[1](https://saami.org/glossary/shotgun/) |
| Bore sizing | Measured in gauge, the number of bore-diameter lead balls weighing one pound; the .410 bore, an actual barrel measurement, is the exception[3](https://saami.org/glossary/gauge/) |
| Ammunition | The shotshell contains a hull, primer, powder, shot or slug, and a wad column that seals gas and protects the pellets[4](https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-10/fired-shotshell-components) |
| Pattern control | A choke, an interior constriction at or near the muzzle, controls shot dispersion; replaceable choke tubes allow the same gun to be matched to the task[5](https://saami.org/saami-glossary/?letter=C) |
| Repeating actions | Pump action patented by Spencer and Roper in 1882; Winchester Model 1897 pump (over one million made, 1897 to 1957) and Browning's recoil-operated Auto-5 semi-automatic, in production from 1902[6](https://www.americanrifleman.org/articles/2016/5/23/looking-back-at-shotgun-history/) • [7](https://www.museum.state.il.us/RiverWeb/harvesting/harvest/waterfowl/tools_techniques/guns/winchester_1897.html) • [8](https://www.browning.com/support/date-your-firearm/shotgun/auto-5-semi-automatic-shotgun.html) |
| US legal threshold | Under the National Firearms Act, a shotgun with a barrel under 18 inches, or a weapon made from a shotgun with overall length under 26 inches, is a regulated NFA firearm[9](https://www.atf.gov/resource-center/questions-and-answers?page=18) |
| Injury share | Shotguns accounted for 5.7% of unintentional firearm injury deaths in 2023 US NVDRS data, behind handguns (62.0%) and rifles (7.6%)[10](https://www.cdc.gov/mmwr/volumes/75/ss/ss7507a1.htm) |
## How it works
**Gauge.** Shotgun bores are sized by gauge (also called bore), a convention inherited from artillery and musket balls: the gauge number is the number of round lead balls of bore diameter that together weigh one pound, so a 12-gauge barrel matches a ball weighing one-twelfth of a pound and is larger than a 20-gauge.[3](https://saami.org/glossary/gauge/) • [11](https://www.nyc.gov/html/ocme/downloads/pdf/Ftox/NYCLAC-Report-Standardization-Project-November-2014.pdf) The .410 bore is named instead for its actual barrel diameter in inches.[3](https://saami.org/glossary/gauge/)
**The shotshell.** A shotshell is a round of ammunition containing multiple pellets for use in a shotgun.[12](https://saami.org/glossary/shotshell/) Its components are the case or hull, a primer that provides the initial spark, the powder charge, the shot or slug, and a wad column separating powder from projectile.[4](https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-10/fired-shotshell-components) • [13](https://fwf.tennessee.edu/wp-content/uploads/sites/24/2020/07/PB-1687-Wlf-Camp-manual.pdf) The wad seals the propellant gases, cushions the shot against deformation as it accelerates down the bore, and sets the correct volume for the powder and shot charges.[4](https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-10/fired-shotshell-components) Plastic replaced paper and fiber in case sidewalls during the 1960s, and modern one-piece plastic wads integrate the gas seal, cushioning, and shot cup.[14](https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-05/alternate-materials)
**Choke and pattern.** A choke is an interior constriction at or near the muzzle end of the barrel that controls how widely the shot disperses; typical US designations run from Full (greatest constriction) through Improved-Modified, Modified, Improved Cylinder, and Skeet to Cylinder (no constriction), and a replaceable choke tube lets one barrel serve several purposes.[5](https://saami.org/saami-glossary/?letter=C) A full-choke barrel shoots tighter patterns at a given distance than a modified choke or an open cylinder bore.[2](https://www.firearmssafetyauthority.govt.nz/sites/default/files/2022-11/Firearms%20Safety%20Code%202022.pdf) Pellet dispersion is also the basis of forensic range estimation: mathematical models of pellet spread allow firing distance to be estimated even when only part of the pattern strikes the target.[15](https://www.sciencedirect.com/science/article/pii/0379073886901441)
## History
The shotgun descends from the fowling piece. A 1671 description in *The Gentleman's Recreation* gives a fowling piece a barrel of "five feet and a half or six feet long," and the side-by-side double-barrel form was essentially settled by British makers during the percussion muzzleloader era.[6](https://www.americanrifleman.org/articles/2016/5/23/looking-back-at-shotgun-history/) London gunmakers such as Joseph Egg, born in France and working in London, produced finely made sporting guns; his ca. 1835 side-by-side self-priming pellet-lock shotgun concealed a reservoir of fulminate pellets inside the stock, and [George IV](https://www.edgepedia.org/george-iv) bought a similar gun from Egg in 1825.[16](https://www.metmuseum.org/art/collection/search/33323) Breech-loading arrived with the pinfire cartridge, exemplified by a decorated 1866 Parisian double-barrel pinfire shotgun exhibited at the Exposition Universelle of 1867.[17](https://www.metmuseum.org/art/collection/search/24957)
**Repeating actions.** Christopher Spencer and Sylvester Roper developed a pump-action shotgun on which Roper was granted a patent in 1882, leading to their Model 1890; the Spencer pump was heavy and clunky, and Winchester's John Browning-designed Model 1893 of 1893 proved too weak for the new smokeless powder, so [Winchester](https://www.edgepedia.org/winchester) quickly replaced it with the Model 1897.[6](https://www.americanrifleman.org/articles/2016/5/23/looking-back-at-shotgun-history/) More than one million Model 1897s were produced from 1897 to 1957, and it became the best-selling slide-action shotgun of its time.[7](https://www.museum.state.il.us/RiverWeb/harvesting/harvest/waterfowl/tools_techniques/guns/winchester_1897.html) John Moses Browning then devised the recoil-operated Auto-5 semi-automatic; production began in 1902 at Fabrique Nationale, his first order ran to 10,000 guns, and the design remained in production into the 1990s.[8](https://www.browning.com/support/date-your-firearm/shotgun/auto-5-semi-automatic-shotgun.html) The exterior shape of the pump action was finalized by the Winchester Model 12, and semi-automatics by the Auto-5, with gas-operated designs following from High Standard and Remington.[6](https://www.americanrifleman.org/articles/2016/5/23/looking-back-at-shotgun-history/) In the mid-20th century the Model 12 set the standard for pumps, later succeeded by the [Remington Model 870](https://www.edgepedia.org/remington-model-870).[18](https://www.nramuseum.org/gun-info-research/a-brief-history-of-firearms.aspx)
## Military and police use
Shotguns served American forces from the colonial frontier onward, where a shot charge or a buck-and-ball load offered high hit probability in close fighting; Confederate cavalry favored double-barrel shotguns, and the Army ordered 200 Winchester M97s for jungle fighting in the Philippines.[19](https://www.benning.army.mil/infantry/magazine/issues/2007/jan-feb/pdfs/jan-feb2007.pdf) • [20](https://armyhistory.org/wp-content/uploads/2017/11/OPComp.pdf) For World War I trench warfare the Model 1897 was adapted into the trench gun, with the 12-gauge barrel shortened from 30 to 20 inches, a heat shield, a bayonet lug for the M1917 bayonet, and all-brass shells carrying nine 00 buckshot pellets; the gun could also slamfire, firing continuously while the trigger was held and the action pumped.[20](https://armyhistory.org/wp-content/uploads/2017/11/OPComp.pdf) The weapon earned nicknames such as "trench sweeper" and "trench broom," and on 19 September 1918 the German government issued a diplomatic protest against its use, citing the 1907 Hague Convention.[20](https://armyhistory.org/wp-content/uploads/2017/11/OPComp.pdf) Pump-action models remained standard US military shotguns through the Vietnam era and later, including the Remington Model 870 and Winchester Model 1200, with the Mossberg M500 following.[19](https://www.benning.army.mil/infantry/magazine/issues/2007/jan-feb/pdfs/jan-feb2007.pdf)
## Sport shooting
Clay target sports are built around the shotgun's pattern. The clay target itself dates to 1880, when George Ligowsky of Cincinnati perfected a clay target and a throwing machine.[21](https://www.ssaa.org.au/disciplines/all-disciplines/shotgun/) Skeet was developed around 1920 by a hunter honing his skills, and sporting clays, in which shooters move between stands while traps throw targets simulating hunting situations, is often called "golf with a shotgun."[22](https://www.ssaa.org.au/stories/shotguns-competitive-shooting-sports-a-brief-history.html) • [23](https://compass.onlinelibrary.wiley.com/doi/10.1111/soc4.12497) The first shoot in America formally titled "sporting clays" was held at Remington's gun club in Lordship, Connecticut, on September 27, 1980, a 30-target event attended by about 90 shooters.[24](https://projectupland.com/shotguns-and-shooting/the-history-of-sporting-clays-in-america/)
At the Olympic and international level, the International Shooting Sport Federation runs Trap, Double Trap, and Skeet events in squads of six, with a hit declared when at least one piece of the clay target is seen falling.[25](https://www.issf-sports.org/issf/championships) [Competition](https://www.edgepedia.org/competition) guns must be smooth-bored, invariably 12-gauge over-and-under types firing lead pellet loads of no more than 24.5 grams per cartridge with pellet diameter not exceeding 2.6 millimeters; the maximum effective range of such a clay target shotgun is considered to be about 50 meters, and the flying target is about 110 millimeters in diameter.[25](https://www.issf-sports.org/issf/championships)
## Regulation
In the United States, the [National Firearms Act](https://www.edgepedia.org/national-firearms-act) of 1934, the first national gun control legislation, imposed a tax on the manufacture, sale, and transfer of listed firearms including short-barreled shotguns.[26](https://time.com/5169210/us-gun-control-laws-history-timeline/) As the Act is enforced currently, a shotgun falls under the NFA when any of its barrels measures less than 18 inches, while a weapon derived from a shotgun is covered when its overall length is less than 26 inches or a barrel is less than 18 inches; by statute, a shotgun is a weapon intended to be fired from the shoulder that uses the burning of the propellant within a fixed shell to discharge, through a smooth-bore barrel, either multiple shot pellets or one projectile with each pull of the trigger.[9](https://www.atf.gov/resource-center/questions-and-answers?page=18) In 1939 the Supreme Court in *United States v. Miller* ruled that Congress could regulate the interstate sale of a short-barreled shotgun under the Act.[26](https://time.com/5169210/us-gun-control-laws-history-timeline/)
## Injuries and environmental regulation
Shotguns are a minority of US firearm deaths. In 2023 National Violent Death Reporting System data covering 50 states, the District of Columbia, and Puerto Rico, handguns accounted for 62.0% of unintentional firearm injury deaths, rifles 7.6%, and shotguns 5.7%, with the firearm type unknown in 24.4% of cases.[10](https://www.cdc.gov/mmwr/volumes/75/ss/ss7507a1.htm) A study of the National Trauma Data Bank from 2007 to 2014 found shotgun wounds comprised 9% of all firearm injuries at US trauma centers, most commonly affecting white men in their 20s in southern states.[27](https://pubmed.ncbi.nlm.nih.gov/32245687/)
[Lead shot](https://www.edgepedia.org/shot-pellet) has been progressively restricted for environmental reasons. The federal ban on lead shot for waterfowl hunting was phased in starting with the 1987-88 season and became nationwide in 1991, applying to ducks, geese, swans, and coots; approved nontoxic alternatives include steel (iron), bismuth-tin, and tungsten-based alloys.[28](https://www.fws.gov/story/2022-04/nontoxic-shot-regulations-hunting-waterfowl-and-coots-us) The restriction responds to lead poisoning in birds that ingest spent pellets, with waterfowl, bald eagles, and California condors of particular concern.[29](https://www.pa.gov/agencies/pgc/wildlife/wildlife-health/wildlife-diseases/lead-toxicosis)
## References
1. [SHOTGUN, SAAMI Glossary](https://saami.org/glossary/shotgun/)
2. [Firearms Safety Code 2022, New Zealand Firearms Safety Authority](https://www.firearmssafetyauthority.govt.nz/sites/default/files/2022-11/Firearms%20Safety%20Code%202022.pdf)
3. [GAUGE, SAAMI Glossary](https://saami.org/glossary/gauge/)
4. [Fired Shotshell Components, NIJ Firearms Examiner Training](https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-10/fired-shotshell-components)
5. [SAAMI Glossary, letter C (Choke, Choke Tube, Choke Markings)](https://saami.org/saami-glossary/?letter=C)
6. [Looking Back at Shotgun History, American Rifleman (NRA)](https://www.americanrifleman.org/articles/2016/5/23/looking-back-at-shotgun-history/)
7. [Winchester 1897, Illinois State Museum, Harvesting the River](https://www.museum.state.il.us/RiverWeb/harvesting/harvest/waterfowl/tools_techniques/guns/winchester_1897.html)
8. [Auto-5 Semi-Automatic Shotgun, Browning](https://www.browning.com/support/date-your-firearm/shotgun/auto-5-semi-automatic-shotgun.html)
9. [Questions and Answers, ATF (NFA definitions)](https://www.atf.gov/resource-center/questions-and-answers?page=18)
10. [Surveillance for Violent Deaths — NVDRS, 50 States, DC, and Puerto Rico, 2023, MMWR](https://www.cdc.gov/mmwr/volumes/75/ss/ss7507a1.htm)
11. [NYC OCME LAC Report Standardization Project (gauge definition)](https://www.nyc.gov/html/ocme/downloads/pdf/Ftox/NYCLAC-Report-Standardization-Project-November-2014.pdf)
12. [SHOTSHELL, SAAMI Glossary](https://saami.org/glossary/shotshell/)
13. [Shotgun ammunition, University of Tennessee Extension manual](https://fwf.tennessee.edu/wp-content/uploads/sites/24/2020/07/PB-1687-Wlf-Camp-manual.pdf)
14. [Alternate Materials, NIJ Firearms Examiner Training](https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-05/alternate-materials)
15. [Mathematical analysis of dispersion of pellets fired from a shot gun, Forensic Science International](https://www.sciencedirect.com/science/article/pii/0379073886901441)
16. [Side-by-Side Self-Priming Pellet-Lock Shotgun, Joseph Egg, The Metropolitan Museum of Art](https://www.metmuseum.org/art/collection/search/33323)
17. [Double-Barrel Breech-Loading Pinfire Shotgun, J. C. A. Brun, The Metropolitan Museum of Art](https://www.metmuseum.org/art/collection/search/24957)
18. [A Brief History of Firearms, NRA Museums](https://www.nramuseum.org/gun-info-research/a-brief-history-of-firearms.aspx)
19. [Shotguns in Combat: Lethality in the Close Fight, Infantry Magazine, January-February 2007](https://www.benning.army.mil/infantry/magazine/issues/2007/jan-feb/pdfs/jan-feb2007.pdf)
20. [Shotguns in American military history, Army History (OPComp)](https://armyhistory.org/wp-content/uploads/2017/11/OPComp.pdf)
21. [Shotgun disciplines, Sporting Shooters' Association of Australia](https://www.ssaa.org.au/disciplines/all-disciplines/shotgun/)
22. [Competitive shotgun shooting sports: a brief history, SSAA](https://www.ssaa.org.au/stories/shotguns-competitive-shooting-sports-a-brief-history.html)
23. [The sociology of U.S. gun culture, Sociology Compass (Yamane, 2017)](https://compass.onlinelibrary.wiley.com/doi/10.1111/soc4.12497)
24. [The History of Sporting Clays in America, Project Upland](https://projectupland.com/shotguns-and-shooting/the-history-of-sporting-clays-in-america/)
25. [Championships and disciplines, International Shooting Sport Federation](https://www.issf-sports.org/issf/championships)
26. [A Timeline of the Major Gun Control Laws in America, TIME](https://time.com/5169210/us-gun-control-laws-history-timeline/)
27. [Shotgun Wounds: Nationwide Trends in Epidemiology, Injury Patterns, and Outcomes from US Trauma Centers, PubMed](https://pubmed.ncbi.nlm.nih.gov/32245687/)
28. [Nontoxic Shot Regulations for Hunting Waterfowl and Coots in the U.S., U.S. Fish & Wildlife Service](https://www.fws.gov/story/2022-04/nontoxic-shot-regulations-hunting-waterfowl-and-coots-us)
29. [Lead Toxicosis, Pennsylvania Game Commission](https://www.pa.gov/agencies/pgc/wildlife/wildlife-health/wildlife-diseases/lead-toxicosis)
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*Topic: Encyclopedia › Technology and the built world › Engineering and manufacturing › Firearms and ammunition › Shotguns and grenade launchers*
*Initially written Sep 17, 2026 · Reviewed: Sep 30, 2026; Oct 15, 2026 · Edited: Sep 30, 2026; Oct 15, 2026 · Last review: Oct 15, 2026*
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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license